Chapter 5: Nominal Versus Effective Rates: Is It Relevant in WACC Calculations?

Using uniformly compounded interest rates is a common principle in financial management. However, one might find it surprising that commonly used corporate finance and accounting valuation textbooks are generally silent regarding the application of this principle in weighted average cost of capital (WACC) calculations and the resultant errors of such an oversight. This study illustrates – using a developed and an emerging market as examples – that the compounding frequency of popular WACC inputs does indeed differ in practice. Furthermore, with sensitivity analyses, we also show that a significant valuation error can occur if nominal rates instead of effective rates are used in the calculation of WACC. We believe that at the very least, students should be made aware of this potential for error. A more appropriate response might be adjustments of textbooks and academic materials to provide more clarity in this regard, which could avoid flawed valuation estimates and as such, incorrect decision-making in practice.